Impaired thalamocortical connectivity in autism spectrum disorder: a study of functional and anatomical connectivity

Abstract

The thalamus plays crucial roles in the development and mature functioning of numerous sensorimotor, cognitive and attentional circuits. Currently limited evidence suggests that autism spectrum disorder may be associated with thalamic abnormalities, potentially related to sociocommunicative and other impairments in this disorder. We used functional connectivity magnetic resonance imaging and diffusion tensor imaging probabilistic tractography to study the functional and anatomical integrity of thalamo-cortical connectivity in children and adolescents with autism spectrum disorder and matched typically developing children. For connectivity with five cortical seeds (prefontal, parieto-occipital, motor, somatosensory and temporal), we found evidence of both anatomical and functional underconnectivity. The only exception was functional connectivity with the temporal lobe, which was increased in the autism spectrum disorders group, especially in the right hemisphere. However, this effect was robust only in partial correlation analyses (partialling out time series from other cortical seeds), whereas findings from total correlation analyses suggest that temporo-thalamic overconnectivity in the autism group was only relative to the underconnectivity found for other cortical seeds. We also found evidence of microstructural compromise within the thalamic motor parcel, associated with compromise in tracts between thalamus and motor cortex, suggesting that the thalamus may play a role in motor abnormalities reported in previous autism studies. More generally, a number of correlations of diffusion tensor imaging and functional connectivity magnetic resonance imaging measures with diagnostic and neuropsychological scores indicate involvement of abnormal thalamocortical connectivity in sociocommunicative and cognitive impairments in autism spectrum disorder.

Discovering frequency sensitive thalamic nuclei from EEG microstate informed resting state fMRI

“…We discovered functionally involved substructures in the thalamus associated with the EEG signals, and we identified their specific frequency tuning for various MS. Further research is needed in order to evaluate thalamocortical networks related to EEG-MS fluctuation. Establishing thalamocortical functional relationships may have important implications for the further understanding of RSNs and may also exhibit clinical relevance (Greicius et al 2007;Nair et al 2013). Steps involved in EEG microstate (MS) informed fMRI analysis.…”

Involvement of Neuroinflammation during Brain Development in Social Cognitive Deficits in Autism Spectrum Disorder and Schizophrenia

“…Underconnectivity in the thalamo-frontal pathway is induced in ASD schoolchildren and adolescents (Cheon et al, 2011). In contrast, functional overconnectivity between the thalamus and temporal lobe occurs in ASD schoolchildren and adolescents, although underconnectivity is found for other cortical regions (Nair et al, 2013). Therefore, it is possible that hyperactivation of the thalamus-temporal lobe connections is due to thalamo-frontal underconnectivity, and that dysconnectivity of these pathways is associated with ASD symptoms.…”

Identifying Corticothalamic Network Epicenters in Patients with Idiopathic Generalized Epilepsy

“…Finally, each thalamic voxel was labeled according to the cortical lobe with the highest t value (ie, "winner take all"). [13][14][15][16] Thus, the thalamus was separately divided into 5 subregions in each group. To compute the functional connectivity strength (FCS) and compare this value between groups, we applied the winner-take-all approach to all participants (n ϭ 209) to limit group bias during thalamic subregion creation.…”